Fuel emulsification system

ABSTRACT

A fuel emulsification system includes a first emulsification device and a second emulsification device. The first emulsification device includes a first outlet end, and a first inlet end in fluid communication with an outlet pipe unit of a tank that receives a mixture of combustible fuel and water. The first emulsification device is configured to emulsify the mixture from the tank into a first emulsion, and to output the first emulsion through the first outlet end. The second emulsification device includes a second outlet end, and a second inlet end in fluid communication with the first outlet end for receiving the first emulsion therefrom. The second emulsification device is configured to emulsify the first emulsion into a second emulsion, and to output the second emulsion through the second outlet end.

BACKGROUND OF THE INVENTION

1. Field, of the Invention

The present invention relates to a fuel processing equipment, more particularly to a fuel emulsification system for forming an emulsion of combustible fuel and water.

2. Description of the Related Art

Ordinary combustible fuel including heavy oil, diesel and residual fuel is widely used in a thermal power apparatus such as an industrial furnace, a kiln, a ship boiler, etc. However, carbon deposition is formed in the ordinary combustible fuel when the ordinary combustible fuel is heated to about 650° before sufficient contact with oxygen. When air is insufficient or the combustible fuel is poorly mixed with air, the carbon deposition cannot be fully burned and thus disturbs the normal operation of the thermal power apparatus so as to cause great loss of energy and serious atmospheric pollution.

Therefore, there is provided a fuel emulsification technique based on a micro-explosion theory. In the fuel emulsification technique, emulsifier is added to the combustible fuel, and then, water is dispersed in the combustible fuel in extremely small globs to form a water-in-oil (W/O) emulsion/in which there are more than 82% of emulsified particles having diameters not larger than 5 um. First, the emulsion is atomized and injected into a combustion furnace in a form of fuel drops. When the fuel drops of the emulsion are burned, the water globs in the emulsion are heated to vaporize so that volumes of the water globs increase rapidly so as to explode and atomize the fuel drops again, i.e., the micro-explosion. As a result, the fuel drops become much smaller atomized fuel drops such that combustion time is relatively short, the combustible fuel is burned relatively completely, thermal efficiency is enhanced, and consumption of the combustible fuel is reduced. In addition, the water vapor formed by the water in the emulsion during the combustion reacts with the carbon in combustion under a high temperature to generate water gas that further burns to increase thermal energy. As a result, smoke and coking attributed to the combustion are alleviated, and the existing coking can be also cleaned. Moreover, the water vapor generated during the combustion has tri-atomic molecules capable of increasing thermal conduction and radiation to improve the thermal transmission effect.

For industrial production and scientific research, since different mixing and dispersing methods directly affect stability of the emulsion of the combustible fuel, the emulsion has to be produced in a certain manner. Conventional methods of emulsifying combustible fuel include, for example, multilayer filtering-net emulsification, mechanical stirring emulsification, electric ultrasound emulsification, resonant-whistle ultrasound emulsification, static emulsification, and pulsed-jet high-shear emulsification.

The multilayer filtering-net emulsification is commonly used, but is not ideal in practice due to requirement of high quality and high temperature of combustible fuel.

A mechanical stirrer is used in the mechanical stirring emulsification to stir a mixture of water and combustible fuel under a certain temperature for emulsification of the combustible fuel. However, since rotation speed of the stirrer does not exceed 3000 rpm, the emulsified particles of the emulsion are not uniform in size and are dispersed unevenly.

The electric ultrasound emulsification has a relatively great stability, and relatively uniform and tiny emulsified particles can be generated in the emulsion. However, this method requires an oscillation source with a high frequency of about 20000 Hz, and hence is not commonly used in practice.

In the resonant-whistle ultrasound emulsification, combustible fuel and water mixed in a certain ratio are ejected through a nozzle and impact a leaf spring on a fixed seat so that the leaf spring vibrates to generate an ultrasound wave so as to disperse the combustible fuel and the water rapidly. The frequency of the vibration of the leaf spring is about 5000 Hz, and thus emulsification effect is better than the mechanical stirring emulsification. However, the service life of the leaf spring is short.

For the static emulsification, a special static emulsification device has a relatively simple structure without any movable component therein.

In the pulsed-jet high-shear emulsification, a rotor rotates fast to make liquid, solid and gas phases, which originally cannot be mixed together, emulsify homogeneously and finely at an instant due to strong kinetic energy generated by high tangential velocity and high-frequency mechanical effect of the rotor.

Since each of the above-mentioned emulsification methods has advantages and drawbacks, it is desired to provide a fuel emulsification system including a plurality of emulsification devices for various emulsification methods. However, a structure of a conventional fuel emulsification system is relatively complicated, i.e., piping arrangement and connections among the components thereof are complicated. Further, the conventional fuel emulsification system often requires maintenance, and the complicated structure thereof makes the maintenance difficult to implement.

SUMMARY OF THE INVENTION

Therefore, an object of the present invention is to provide a fuel emulsification system that has a relatively simple structure facilitating installation thereof and that is capable of forming an emulsion of combustible fuel and water without requiring addition of an emulsifier.

Accordingly, a fuel emulsification system of this invention is configured to form an emulsion of combustible fuel from a fuel supply and water from a water supply. The fuel emulsification system comprises a fuel-feeding pipe, a water-feeding pipe, a tank, a first emulsification device, and a second emulsification device.

The fuel-feeding pipe is configured to be connected to the fuel supply for feeding combustible fuel, and the water-feeding pipe is configured to be connected to the water supply for feeding water. The tank is in fluid communication with the fuel-feeding pipe and the water-feeding pipe for storing a mixture of the combustible fuel from the fuel-feeding pipe and the water from the water-feeding pipe. The tank includes an outlet pipe unit configured to output the mixture of the combustible fuel and the water.

The first emulsification device includes a first outlet end and a first inlet end that is in fluid communication with the outlet pipe unit of the tank for receiving the mixture of the combustible fuel and the water therefrom. The first emulsification device is configured to emulsify the mixture into a first emulsion and to output the first emulsion through the first outlet end.

The second emulsification device includes a second outlet end and a second inlet end that is in fluid communication with the first outlet end of the first emulsification device for receiving the first emulsion therefrom. The second emulsification device is configured to emulsify the first emulsion into a second emulsion and to output the second emulsion through the second outlet end.

BRIEF DESCRIPTION OF THE DRAWING

Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiment with reference to the accompanying drawing, of which;

FIG. 1 is a schematic diagram of a preferred embodiment of a fuel emulsification system of this invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIG. 1, a preferred embodiment of a fuel emulsification system of this invention is configured for forming an emulsion of combustible fuel from a fuel supply (not shown) and water from a water supply (not shown). The fuel emulsification system includes a fuel-feeding pipe 10, a water-feeding pipe 20, a tank 30, a regulating valve 40, a pre-emulsification device 50, a first emulsification device 60, a second emulsification device 70, and a storage tank 80.

The fuel-feeding pipe 10 is configured to be connected to the fuel supply for feeding combustible fuel (such as heavy oil, diesel, residual fuel, etc.) to the tank 30. Along a feeding direction of the combustible fuel from the fuel supply to the tank 30, the fuel-feeding pipe 10 is provided with a ball valve 14, an oil filter 11, an electromagnetic regulator valve 12 and a flow meter 13.

The water-feeding pipe 20 is configured to be connected to the water supply for feeding water to the tank 30. Along a feeding direction of the water from the water supply to the tank 30, the water-feeding pipe 20 is provided with an electric heater 24, a ball valve 21, an electromagnetic regulator valve 22, and a flow meter 23.

The tank 30 is in fluid communication with the fuel-feeding pipe 10 and the water-feeding pipe 20, and is adjacent to the flow meters 13, 23. The tank 30 is configured to store a mixture of the combustible fuel from the fuel-feeding pipe 10 and the water from the water-feeding pipe 20, and includes an outlet pipe unit 31 configured to output the mixture of the combustible fuel and the water. The outlet pipe unit 31 includes a first passage 311 in fluid communication with the pre-emulsification device 50, and a second passage 312 in fluid communication with the first emulsification device 60. In addition, the output pipe unit 31 is provided with a pressure pump 32 and a parallel pair of filters 33 in a series connection with the pressure pump 32.

In particular, the second passage 322 includes a first branch 313 fluidly connecting the first emulsification device 60 and the second emulsification device 70, and a second branch 314 provided with an ultrasound pulsed-jet emulsifying mixer 317 in fluid communication with the tank 30. In other embodiments, the ultrasound pulsed-jet emulsifying mixer 317 on the second branch 314 of the second passage 312 may be replaced with a different type of an emulsifying mixer, for example, a multilayer filtering-net type emulsifying mixer, a mechanical stirring emulsifying mixer, an electric ultrasound emulsifying mixer, a resonant-whistle type ultrasound emulsifying mixer, a static emulsifying mixer, or a pulsed-jet high-shear emulsifying mixer.

The regulating valve 40 is disposed between and in fluid communication with the first and second emulsification devices 60, 70 through the first branch 313, and is fluidly connected to the tank 30 through the second branch 314. The second passage 312 further includes a pair of bypass channels 315 fluidly connecting the first emulsification device 60 respectively to the first and second branches 313, 314 across the regulating valve 40, and a plurality of manual valves 316 mounted on the first and second branches 313, 314 and the bypass channels 315.

The pre-emulsification device 50 includes a front-end emulsifying mixer 51 in fluid communication with the first passage 311 of the output pipe unit 31, and a parallel pair of rear-end emulsifying mixers 52 in a series connection with the front-end emulsifying mixer 51. Each of the rear-end emulsifying mixers 52 has an output end 521 fluidly connected to the tank 30.

The first emulsification device 60 includes an opposite pair of a first inlet end 61 and a first outlet end 62. The first inlet end 61 is in fluid communication with the second passage 312 of the outlet pipe unit 31 of the tank 30 for receiving the mixture of the combustible fuel and the water therefrom. The first emulsification device 60 includes a first emulsifying mixer 63 between the first inlet end 61 and the first outlet end 62.

The second emulsification device 70 includes an opposite pair of a second inlet end 71 and a second outlet end 72. The second inlet end 71 is in fluid communication with the first outlet end 62 of the first emulsification device 60 through the second passage 312 and the regulating valve 40, and the second outlet end 72 is fluidly connected to the storage tank 80. In this embodiment, the second emulsification device 70 further includes a second emulsifying mixer 73, a third emulsifying mixer 74 and a flow meter 75 between the second inlet end 71 and the second outlet end 72. The second and third emulsifying mixers 73, 74 are fluidly connected to each other in a series connection or a parallel connection.

In practice, each of the front-end and rear-end emulsifying mixers 51, 52 of the pre-emulsification device 50, the first emulsifying mixer 63 of the first emulsification device 60, and the second and third emulsifying mixers 73, 74 of the second emulsification device 70 is independently selected from the group consisting of a multilayer filtering-net type emulsifying mixer, a mechanical stirring emulsifying mixer, an ultrasound emulsifying mixer, an ultrasound pulsed-jet emulsifying mixer, a resonant-whistle type ultrasound emulsifying mixer, a static emulsifying mixer, a pulsed-jet high-shear emulsifying mixer, and combinations thereof. In this embodiment, the first emulsifying mixer 63 is a pulsed-jet emulsifying mixer, the second emulsifying mixer 73 is an ultrasound emulsifying mixer, and the third emulsifying mixer 74 is a pulsed-jet high-shear emulsifying mixer.

In this embodiment, the combustible fuel is preheated so as to achieve expected fluidity before it is transmitted from the fuel supply to the fuel-feeding pipe 10. Then, the preheated combustible fuel passes through the oil filter 11, the electromagnetic regulator valve 12 and the flow meter 13 in sequence, and then, flows into the tank 30. In the meantime, the water is delivered into the water-feeding pipe 20, and is preheated by the electric heater 24 to reach the same temperature as the preheated combustible fuel. Then, the preheated water passes through the ball valve 21, the electromagnetic regulator valve 22 and the flow meter 23, and flows into the tank 30. By using the electromagnetic regulator valves 12, 12 and the flow meters 13, 23, a programmable logic controller (PLC) (not shown) can be used to regulate an inflow amount of the combustible fuel and an inflow amount of the water respectively according to a predetermined ratio of the combustible fuel to the water configured in the PLC.

The preheated combustible fuel and water are mixed in the tank 30, and the mixture of the combustible fuel and the water thus formed is outputted through the outlet pipe unit 31. After pressurizing by the pressure pump 32 and filtering by the filters 33, the mixture of the combustible fuel and the water is divided to flow into the first and second passages 311, 312. In the first passage 311, the mixture flows through the front-end and rear-end emulsifying mixers 51, 52 of the pre-emulsification device 50 so that the mixture is pre-emulsified into a pre-emulsified mixture by the pre-emulsification device 50. Then, the pre-emulsified mixture flows back to the tank 30 via the output ends 521 of the rear-end emulsifying mixers 52, and mixes with the mixture stored in the tank 30. By feeding the pre-emulsified mixture into the tank 30, the combustible fuel and the water stored in the tank 30 can be mixed and emulsified preliminarily.

On the other hand, in the second passage 312, the mixture of the combustible fuel and the water flows into the first emulsification device 60 through the first inlet end 61, and the first emulsifying mixer 63 is operable to emulsify the mixture into a first emulsion. Then, the first emulsification device 60 outputs the first emulsion through the first outlet end 62. Subsequently, the regulating valve 40 is operable to regulate a flow amount of the first emulsion to the second emulsification device 70 through the first branch 313 so that an excess amount of the first emulsion may flow back to the tank 30 through the second branch 314 and the ultrasound pulsed-jet emulsifying mixer 317. The first emulsion flows into the second emulsification device 70 through the second inlet end 71, and the second emulsifying mixer 73 is operable to emulsify the first emulsion into a second emulsion. The second emulsion is outputted to the storage tank 80 through the second outlet end 72 and stored in the storage tank 80, and can be provided through a fuel outlet 81 of the storage tank 80 for direct use on-site. Further, after the second emulsifying mixer 73, the second emulsion may flow into the third emulsifying mixer 74 for additional emulsification before flowing out of the second outlet end 72.

When the regulating valve 40 has a fault or is under maintenance, the manual valves 316 can be used for manual regulation of the flow amount of the first emulsion to the second emulsification device 70. It should be noted that the pre-emulsification performed by the pre-emulsification device 50 in the first passage 311 and the emulsification performed by the first and second emulsification devices 60, 70 in the second passage 312 may be implemented at the same time or may be implemented independently according to different requirements.

In addition, for monitoring the effect of emulsification, the fuel emulsification system may be provided with a plurality of acoustic intensity detectors 90 disposed after the front-end emulsifying mixer 51 of the pre-emulsification device 50, the first emulsification device 60, and the second emulsifying mixer 73 of the second emulsification device 70, respectively.

The fuel emulsification system may be further provided with a control valve 103 disposed on the fuel-feeding pipe 10 and a steam pipe 101 disposed between the control valve 103 and the filter 11. When the fuel emulsification system stops operating, the control valve 103 can be closed after exhausting the fuel and the emulsion in the fuel emulsification system, and then, the steam pipe 101 can be connected to a steam source (not shown) providing steam flowing through the pipes and the devices of the fuel emulsification system for cleaning the pipes and the devices. Finally, the sanitary steam flows to the storage tank 80, and sewage in the storage tank 80 is exhausted through a sewage outlet 82, thereby removing residual fuel in the fuel emulsification system.

Furthermore, the fuel emulsification system may be also provided with a bypass pipe 102 connecting the fuel-feeding pipe 10 and the second outlet end 72. When the pre-emulsification device 50 and the first and second emulsification devices 60, 70 are under maintenance or are replaced, a combustion equipment that is connected to the fuel emulsification system can still operate normally.

In conclusion, by virtue of the pre-emulsification device 50 and the first and second emulsification devices 60, 70, sound waves and ultrasound waves with high intensity are transmitted in the fluid (i.e., the combustible fuel and the water) due to hydrodynamic force of the fluid per se. When the acoustic intensity of the waves reaches a certain level, a cavitation effect occurs in the fluid such that molecular chains in the combustible fuel are decomposed and recombined so as to generate emulsification with the water. Finally, a water-in-oil (W/O) type of suspended and inseparable emulsion of the water in a dispersed phase and the combustible fuel in a continuous phase is formed. The water globs in the emulsion have very small diameters, are dispersed homogeneously, and have stable characteristics. Thus, the emulsion produced by the fuel emulsification system of this invention can be widely used without adding additional agents (for example, emulsifier). In particular, more than 95% of the emulsified particles of the emulsion processed by the fuel emulsification system of this invention have diameters smaller than 5 um. As a result, the combustible fuel processed thereby makes a combustion equipment connected to the fuel emulsification system achieve a combustion exhausting rate of more than 99%.

Moreover, when combustible fuel has relatively higher viscosity, a ratio of the water to the emulsion is relatively higher so that the combustible fuel is saved and pollution is reduced. The maximum ratio of the water to the emulsion produced by the fuel emulsification system of this invention is about 30%, and up to 25% of the combustible fuel is saved. Accordingly, discharge amount of carbon monoxide, sulfur oxides and nitrogen is significantly reduced. According to the condition of external combustion, when the ratio of the water to the emulsion ranges from 15% to 20%, the cost of the fuel 180# can be reduced by more than 10% and the distribution air volume can be reduced to about 10%.

The second and third emulsifying mixers 73, 74 of the second emulsifying device 70 may operate independently or cooperate such that the fuel emulsification system of this invention can still operate when either one of the second and third emulsifying mixers 73, 74 requires maintenance or replacement. The productivity of the fuel emulsification system can achieve 1 T/H to 50 T/H. In addition, the fuel emulsification system can be controlled by the PLC so as to facilitate the operation thereof.

While the present invention has been described in connection with what is considered the most practical and preferred embodiment, it is understood that this invention is not limited to the disclosed embodiment but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements. 

1. A fuel emulsification system for forming an emulsion of combustible fuel from a fuel supply and water from a water supply, said fuel emulsification system comprising: a fuel-feeding pipe configured to be connected to the fuel supply for feeding combustible fuel; a water-feeding pipe configured to be connected to the water supply for feeding water; a tank in fluid communication with said fuel-feeding pipe and said water-feeding pipe for storing a mixture of the combustible fuel from said fuel-feeding pipe and the water from said water-feeding pipe, said tank including an outlet pipe unit configured to output the mixture of the combustible fuel and the water; a first emulsification device including a first outlet end and a first inlet end that is in fluid communication with said outlet pipe unit of said tank for receiving the mixture of the combustible fuel and the water therefrom, said first emulsification device being configured to emulsify the mixture into a first emulsion and to output the first emulsion through said first outlet end; and a second emulsification device including a second outlet end and a second inlet end that is in fluid communication with said first outlet end of said first emulsification device for receiving the first emulsion therefrom, said second emulsification device being configured to emulsify the first emulsion into a second emulsion and to output the second emulsion through said second outlet end.
 2. The fuel emulsification system as claimed in claim 1, wherein said outlet pipe unit of said tank includes a first passage and a second passage that is in fluid communication with said first emulsification device; said fuel emulsification system further comprising a pre-emulsification device in fluid communication with said first passage for pre-emulsifying the mixture of the combustible fuel and the water stored in said tank into a pre-emulsified mixture that flows back to said tank and mixes with the mixture stored in said tank.
 3. The fuel emulsification system as claimed in claim 2, further comprising a regulating valve disposed between said first and second emulsification devices and fluidly connected to said tank.
 4. The fuel emulsification system as claimed in claim 2, wherein said pre-emulsification device includes a front-end emulsifying mixer in fluid communication with said first passage of said output pipe unit of said tank, and a parallel pair of rear-end emulsifying mixers in a series connection with said front-end emulsifying mixer and in fluid communication with said tank to output the pre-emulsified mixture that flows back to said tank.
 5. The fuel emulsification system as claimed in claim 4, wherein each of said front-end and rear-end emulsifying mixers is independently selected from the group consisting of a multilayer filtering-net type emulsifying mixer, a mechanical stirring emulsifying mixer, an ultrasound emulsifying mixer, an ultrasound pulsed-jet emulsifying mixer, a resonant-whistle type ultrasound emulsifying mixer, a static emulsifying mixer, a pulsed-jet high-shear emulsifying mixer, and combinations thereof.
 6. The fuel emulsification system as claimed in claim 1, wherein said second emulsification device further includes a pair of emulsifying mixers fluidly connected to each other in one of a series connection and a parallel connection.
 7. The fuel emulsification system as claimed in claim 6, wherein each of said emulsifying mixers of said second emulsification device is independently selected from the group consisting of a multilayer filtering-net type emulsifying mixer, a mechanical stirring emulsifying mixer, an ultrasound emulsifying mixer, an ultrasound pulsed-jet emulsifying mixer, a resonant-whistle type ultrasound emulsifying mixer, a static emulsifying mixer, a pulsed-jet high-shear emulsifying mixer, and combinations thereof.
 8. The fuel emulsification system as claimed in claim 1, wherein each of said first and second emulsification devices further includes at least one of a multilayer filtering-net type emulsifying mixer, a mechanical stirring emulsifying mixer, an ultrasound emulsifying mixer, an ultrasound pulsed-jet emulsifying mixer, a resonant-whistle type ultrasound emulsifying mixer, a static emulsifying mixer, and a pulsed-jet high-shear emulsifying mixer.
 9. The fuel emulsification system as claimed in claim 1, further comprising a storage tank in fluid communication with said second outlet end of said second emulsification device for storing the second emulsion received therefrom. 